The present invention relates to video apparatuses provided with a plurality of interfaces such as an HDMI (High-Definition Multimedia Interface) (Registered Trademark).
The HDMI has now been widely circulated as an interface for simultaneously transmitting, directly or via an audio system, non-compressed video signal and audio signal from a video signal source such as a HDD (Hard Disc Drive) recorder or an STB (Set-Top Box) to a display apparatus such as a TV (television) receiver, a monitor or a projector.
Patent document JP-A-2009-10537 describes as a task “a bidirectional communication at a high speed with compatibility preserved” and describes as means for attaining the task that “when a bidirectional IP communication is performed between HDMI source 71 and HDMI sink 72 by making use of CEC line 84 and signal line 141, changeover control section 121 controls switch 133 in such a manner that, for data transmission, the switch 133 selects a partial signal constituting a differential signal from converter section 131, and for data transmission, the switch 133 selects a partial signal constituting a differential signal from receiver 82, while when a bidirectional communication is performed only by making use of CEC line 84, the changeover control section 121 controls the switch 133 in such a manner that the switch 133 selects a CEC signal from the HDMI source 71 or from the receiver 82.” (See abstract).